Baseline (all patients) i. Informed consent and treatment randomization ii. Biochemical analysis: ALT, AST, total cholesterol and HDL, triglycerides iii. CD4 count, CD8 count iv. Plasma HIV-RNA v. Clinical evaluation, anamnestic and demographic data: sex, age, risk factor for HIV infection, CDC AIDS classification, time on ART, time on current HAART, previous antiretroviral drugs, previous sub-optimal ARTs, current antiretroviral drugs, presence and grade of lipodystrophy, time with HIV-RNA below detection, nadir CD4, CD4 at start of antiretroviral therapy